Electric tool.



PATENTED MAY 14, 1907.

O. A. KENYON.

ELECTRIC TOOL.

APPLICATION FILED 0092.23. 1906.

LII. -iiilli n a )M4/Leos e o UNITED STATESA gam? onirica.

cris ALLEN KENYoN, lor NEwYoRK, N; Y.

ELECTRIC jTooL.`

To all Inkom/it may concern.-

Be it known that I, O'rrs ALLEN KENYON la citizen'of the United States, residing at New York city, in the county of New York"- and State of New York, have-invented cering, drilling, and similar functions.

' he principal object is to provide a tool of this class in which thelength oi the stroke is automatically adjusted and varied to suit the requirements, and in which a hammer blow is exerted and is followed by immediate.

I retraction of the tool from the work.

, Other objects of the invention are to avoid injurious sparking at the contacts, and provide a strong and simple tool which is not liable toderangement in use, and which is easily assembled or taken 'apart when deslre In the drawings: Figure 1 is a longitudinal sectional view 'of an electric-hammerl or tool embodying the principles of my invention; Fig.' 2 is a section on the line II-II of Fig.1 1;' Fig. 3 .is a section on the line III-III ofFig. 1.'

Riveting hammers,- rock drills, cement tam ers, and a variety `of other a pliancesl use in the arts require the poweriu reciprocation of'a part under the control of an operator. So Jfar as Il am aware-electric tools of thisdescription have not been arranged to ycompensate exactly for the varying position of the Work. In other words, electric hamlmers have ordinarily had a substantially 'immediate retraction iiXed stroke, so that unless the position oi the workvcorresponde'd exactly tothe length of this stroke,` -a proper b low followed by the of the tool could not be obtained."

In carryingoutmy invention `I provide means' by which the'tool is immediately'retracted after it has made its impact against the work,'and this isl true whether the tool meetsthe work early or late in the path oi its normal stroke. This Aresult is securedv by having `a supplemental ycontact or'switch broken by'the impact of the tool with the specification of 'Letters Patent'. Application lied October 23, 1906. Serial NoHSOJSS.

Patenedmay 1 4, 19047.

work regardlessoflwhere'this happens to voccur with respect to thenormal stroke. f

Referring to the-drawings, 1 denotes a frame or casing which is preferably cylindrical in form, and has a longitudinal chamber 2,A throughout its length.- The reciproleating part 3 is guided within the -irame or casing 1 so asto have a longitudinal movement therein.' For :this purpose the lower end of the reciprocating part or plunger 3 is received in' a sliding collar 4, guided by the in- -terior cylindrical Wall 5 of the frame or casing. The tool or tool carrier 6 is fixed to the sliding "collar 4', and a spring V7 :is 'interposed beplunger, but is capable of movement toward thefplunger lwhen sulicient force is exerted upon the spring. The outward movement is limited by the engagementv of the shoulders S of the collar l with a flange 9 at the lower' end of the plunger.

The plunger 3 is preferably lmadre of nonmagnetic material, and has attached to its upper end an iron, core 10, which maybe' This laminated or radially slotted as shown. core extends upward through a solenoid 1.1

fixed Within the casing 1, and which has' electrical connections by which it is energized, and which are la'ter more particularly described. The upper end of the core l0v is enlarged, as shown at 12, this enlargement being guidedbythe interior walls 13 of the chamber 2. In order to prevent the reciprocating part from having an angular move-- ment within the casing, the chamber 2 is vertween the plunger 3 and the tool, sothat the i latter is normally impelled outward from the tically slotted, as shown at 14, where it guides the core 10, and the enlargement 12 of the core isl formed to fit the slots 14.

1 5 indicates a spring coiled within the casing and bearing upwardly against the enlargement 12 of-the core 10, so that the core and its connected parts are normali, iinpelled into the extreme limit of their upward movement. When, owever, the solenoid v11 is energized,th'e core 10 is drawn downward, therebyfimpelling the plunger 3 and the'tool 6 toward the work.

Thecircuit by which the solenoid 11 is ci ergized includes Atwo separate devices by which it is openedto permit the tool to make itsreturn stroke: The first I shall terni the IOG main switch, and the second the supplemental switch. The mam switch, designated broadlyA at 16, A'may be made in any desired rings 19 and A20, insulated from one another 1o and from the casing, butI supported thereby. The ring 20 isin metall e connection with the leading-in wire L1', while the ring 19 is connected to the winding '22 bt a small magnet 23.

24 indicates an armature for the magnet 23 .which is held thereby in contact with the two springs 17 andr 18 when the magnet is energized. When the'l magnet is de-ener gized, the armature drops away 'from the springs 17 and 18 so that the electric connection between them is interrupted.

'The circuit from the winding 22 is com-v pleted to the 'solenoid and from thence to the outgoing terminal 25, but in this connection I employ special means which constitutes an important tea-ture of the invention. y 26 and 27 indicate strips which are vertically inset in the slots 14, but insulated from the metal ol" the easing. The strip 26 iseoncore, but are capable ot being bridged or connected by a spring plate 30. This plateis fastened to a stem 31, which extends down ward through the core 10, and through the plunger 3', and is fastened to the tool 6. The spring plate 30 is capable of vertical yielding movement by its elasticity and is arranged to be vertically adjustable on the stem 31 by means ot' the sleeve 32 which ma)7 be threaded to 'the stem and which directly supports the plate 30.

33 'indicate lock nuts for fixing the adjust# ment.

The operationis as follows:' Considering the parts in the positions shown, the electric circuit is interrupted. between the springs 17 'and 18, so that the spiral spring 15 is eiective toimpel the'core 10 upward. When'the core arrives at the limit of its upward move- 60 ment, it impinges against-the armature 24,

' and moves said armature upward, soA as -to establish a connection between the blades 17 and 18. Current is now free to How through wire 2,1, ring 20, blade 18, armature nected to the winding 22, and the strip 27 is p mature.

insulated from one another and from the 24, blade 17,-ring- 19, winding 22, strip 26, blade spring 28, plate 30, blade s1' ring.29, strip 27, and iinall'y through the windings of the solenoid 11 and the outgoing terminal 25. The solenoid is thereby energized to attract the core lOwhich is at this time in a' position to be drawn downward. The downwardstroke proceeds until the plunger' arrives at the bottom of its stroke or until thetool 6 strikes against the work which is being operated upon. In the latter case the tool 1s arrested by theimpact and the spring 7 compressed by the downward movement of plunger 3', which continues by its momentum and the power of the solenoid. The relative movement of the tool and the plunger is transmitted to the stem 31, so that the spring plate 30 is moved upward oil of the two metallic contacts 28, 29. inasmuch as the current for 'the energization ot 'the solenoid traverses` this path, it is evident that the solenoid will be cle-energized. Not only is the solenoid ile-energized to allow the spring 15 to commence its return movement, but the magnet 23, also lying in the main circuit, is also de-energizcd so that the arn'iaturc 24 falls to break contact between he springs 17 and 18. y Therefore, tl'iesolenoid. 11 wil not again be energized until the reciprocating part is moved upward to the extreu'ic limit of its movement and impinges against the ar- When the plunger strikeis` the armature the circuit between the blades 'l 7 and. 18 is again completed. In the meantime the spring 7 has moved the tool and plunger inlo theirnormal relation, so that contact is established by the plate 30. The soenoid is, therefore, energized and draws down its core to repeat the above-operation.

i It will be observed that the lorec ol' the spring 7, and the spring p e 30, eonlr'ols the power of the stroke. This happens since if these springs 7 are ver," still' a much greater resistance in 'the path of the too' is necessari,r to compress the spring. I have provided means by which the tension of the springs are adjusted so that the force of the stroke can. be controlled. This is accomplished. by the threaded sleeve 32 which may he screwed downward so as to impel the spring plate 3() against its contacts with greater or less pressure. When the device is used it is merely necessary for the operator to initially com plete the circuit by any means, as for example, by a push button 34 and move the tool into proximity to the work, after which the action is automatic, the tool continuing to reciprocate and strike the work with a predetermined' impact regardless of whether or not the position of the frame corresponds to its normal length of stroke. Thereafter it is only necessary for the operator to keep the casingin approximately the right position with respect to the work, somewhere between IIO I the limits of theI 'stroke' Aof :Since the reciprocating parts'.

where an 4arc can .be drawn is at the plate 30.

furthermoreseparates from them with very great suddenness, the formation of a destructive arc is prevented. Any slight blistering or'burningof the contacts is not harmful, be-

cause the force of their engagement with the Afeature of the invention lies in having the apparatus adapted to exert a steady pressure f against the work ifdesired. It will be seen that when the tool is resting steadily against i make a working stroke, a switch for inter-v justingthe amount of said foro I 5. n

the work there is no impact to compress .s pring 7 and open the circuit at the plate 30.

e steady' force of the solenoid is not sufcient t0 accomplish this.

Whatl claim, isyz y 1 In an appliance ofthe class described, atoo against the work, and a switch for breaking the circuit of said means simultaneously with the blow -or impact ofthe to'ol against the' work.- 2. In an appliance ofthe class described, a' tool, electric means for impelling said tool,

a switch for` breaking the circuit of said means simultaneously with the blow or impact of the tooly a ditional switch or immediately afterward breaking such circuit at another point.

In an appliance of the class described, a tool, electric means for impelling said tool to make a working stroke, a main switch, a supplemental switch, and means actuated by the 'impact of the tool with the work for breaking the circuit of said electric means first at the supplemental switch and then at the main switch. v

4. In an appliance of the class described, a tool, electric means for impelling said tool to rupting the circuit of said means actuated by the impact of the tool against the work with a predetermined force, and means 'for adan appliance of the class described, a tool, electric means for impelling said tool against the work, a

against the work,"and a switch movablewith' the tool and arrange'dto break the circuit of will .be observed that-.the only place this plate engages two contacts and' electric means for impelling said tool ainst the work,'and an admagnet operated switchv for mamtalm a closed circuit 1n 'sald elecsaid means simultaneously with the impact ofthe tool against the wor 7. In an appliance of the class described,.a'

tool, electric means for impelling said tool against the work, a switchcarried by said tool for interrupting the circuit of said means, and means carried by the tool for opening said'switch when thetool strikes the Work with a predetermined blow or impact.

y 8. In an applianceof the classdescribed, a solenoid, a tool reciprocated thereby, and means actuated by the impact. of the tool against lthe work for breaking thezcircuit of said solenoid.

" 9. In an appliance of the class described', ai

solenoid, a tool adapted to Ibe moved thereby solienoid simultaneously with the impact of the tool against the work.

and mea-ns for breaking the circuit ofthe 10. In an appliance of the class described,

a solenoid, a tool adapted to be moved thereby, a` main switch, a supplemental switch, and means forbreaking the circuit ofsaid solenoid at such supplemental switch simultaneously with the lmp the work, and immediately afterward breaking said circuit at said main switch.

11.- In an appliance of the classdescribed, r

a reciprocating part, a solenoid for moving said part, a switch for controlling said solenoid., and means'carried by said part but having a relative movement with respect thereto for opening said switch.

act'of the tool against.

12. In an appliance of the class described, y

a reciprocating part, a solenoid, means carried by said part for momentarily breakin los the circuit of said solenoid, and additiona means for breaking the circuit ofthe solenoid during the entire period of the return stroke of saidreciprocating part.

' 13.- In an appliance of the-class described, a frame or casing, a solenoid fixed thereto, a reciprocating part having a tool, a'plunger, and a core cured-to the tool and passing throughsaid plunger and core and having a movement relative to said core, a supplemental switch carried by said core and opened by the movement of the stem With respect thereto, means for completing the circuit of saidV solenoid through said switch,` a mainswitch adapted Within' said solenoid, a stem se- .f

to be closed by the upward movement of said core, andmagnetic means for maintaining said main switch closed during the down- I ward movement ofthe core and while the circuit is closed at said supplemental switch, allas and for the purpose set forth.

14. In an appllance of the class described,

a frame or casing having a central longitudiw nal chamber, la'sole'noid'fixed wxthimsaid, chamber,

a reciprocatin a plungerand a core wit an enlargement on said core, a pair of sprm part having-altoolf i2 5 'n said solenoid and blades 'carried by said enlargement. a switc supported 'Within said chamber and insulated for normally making an electric connection' mental switch and said solenoid for energizbetween said blades, strips longitudinally l ing the latter. v Y 1o In Witness whereof, I subscribe my signatherefrom and in the path of said spring ture, in the presence of two Wtn ssea blades, a main switch at lche upper end of the. OTIS ALLEN KEN YON. casing, magnetic means for maintaining said Witnesses: mam switch closed, and a circu1t including vEDWARD D. C. SPERRY,

said main switch, said strips, said supple- WALDO M. CHAPIN. 

